Drilling apparatus



' particularly to lin these respective ball Patented Dee.' 29, 1942 l Michael D. carleton,

Reed-Roller Bit Company, corporation of Texas Application May 18 1940,

3 Claims. (01.'255-71) This invention relates to cross roller bits-and thereof.

In the mounting bits provision must bel made for of side cutters for cross roller taking the mul- 'titude of very great stresses placed upon the side cutters during the operation o f a cross roller bit.

great, they 'may' Although these stresses are very all be resolved into radial loads and end thrusts. ltv is an object of this invention to provide a the bearings for the sidel cutters bearing for a side cutter which can be easily and cheaply vmanufactured and yet Whichwill'be caf' pablo of taking both the radial loads andend thrusts to which the cutters are subjected.'

, Another object yof this invention is to provide such a structure which may be easily and quickly assembled and which will. not be susceptible of becoming disassembled in use.

axes or romrunning Other objects and advantages of this invention will become apparent from the following description taken in connection withthe accompanying y drawing.

In the drawing a single figure illustrates a sideview partly in vertical cross section of a cross vroller 4bit having bearings for its side` cutters constructed in accordance with this invention.

.In this instance, the bit consists of afshank having threads 2 thereon and having legs 3 and l suitably secured to its lower` end. A suitable plate 5 having slush openings Stherein is provided for tions supported by said legs, a pair of side cutters portion of said bridge ad-` thrusts yin an inward ,3o

directing the slush against the teeth of there-` 4 spective cutters. Each cross roller cutters 8.

of the legs 4 is adapted to provide a support for one outer end of a cross side cutters having,v a'pair' of. ball 'ra'ces'rcorree f cutter shaft 1 on which are rotatablyl mounted Y sponding to the, ball'racesonfsaid `bridge and and eachis provided with a downwardly and in Y shaft-like end portionl ends of the bridge .l l.

` wardly extending opening adapted to receive a IIJ on one of the opposite The bridge Il, as -illustrated, embraces and serves as a support-,for the central portion oi the cross cutter shaftv I and adjacent its outer ends is formed with two ball' The side cuttersv It are bearing races' l2 and i3. provided with corresponding ball races, and withraces there are placed'two rows oi balls i5 and i6 for rotatably supporting each side cutter.

In thevforrn illustrated theilegs 3 Yare formed` separate from each other and. from the shank i and are Welded to the shank as shown at i1.

In assembling the bit just described the balls l5 are iir'st put in place withintheraces l2 on the bridge.

over the ends of the The side cutters I4 are then placed bridge and against Houston,` Tex., assigner to Houston, Tex., a

sei-ilu No. 335,880

legs 3 of the bit. Thelegs 3 are then welded in place and the' ends l0 :are welded in the legs 3 as shown at I8.

It will be appreciated that in the construction just described the two sets of balls I5. and `I6 withinthe respective side cutters will tendtoisupport these side cutters ragainst radial' loads and end thrustsfand will very eiectively tend to'prevent the side cutters from tilting with respect to their Y in or running out with respect to thek axis of kthe bit during the operation l It will Vfurther be seen that the device will be relatively simple toconstruct andrugged and durableinoperation.

Having describ d my invention,:I claim: l. Ina roller bit, a. shank having yside cutter legs extending downwardly therefrom,` a. bridge extending between said legs and having end por,-

surrounding the end :jacent said legs,`each end oi said bridge `having an inner ball race adapted to'receive balls fortaking endthrusts in eitherv the bridge for taking end thrust inv an outward direction,

lying adjacentthe opposite ends ofIv said side cutv4ters respectivelyLand balls inlsaid ball-races. u

. 2. In a roller, bit, a shank having downwardly extending cutter legs thereon, ybetween said legs and having its opposite ends eneased and supportedv by sam legs, tneepposite vend portions iofvsaid bridge' inwardly of said legs vproviding bearings, a pair ot "side cutters 'on said bearings, a `pair of outwardly` facing -flanges on said bridge adjacent said bearings providing outwardly facing ball ',.races for taking inward thrust, the inner surl tively, and balls in said ball race'sfor ltaking the c the balls 55 thrust and radial loads from said cutters.V

faces of each of said legs being provided with 'inwardly facing' ball races .adaptedv toi'take outyward thrust, the bearing portions of lsaid bridge j having ball races .complementaryv to jsaid lenti thrust receiving races respectively,.-and'eachrof said cutters having towards the opposite ends of said'cutter's respecput in place within thefy direction and an outer ball f race adapted to 'receive balls Io'rftaking end direction, each of said legs y having a ball race adapted to complement saidl ay bridgeextending the inner endportionsof a vpair of ball races facing.`

3. In a roller bit. a shank having downwardly extending cutter legs thereon, a bridge extending between said legs and having its opposite ends engaged and supported by said legs, the opposite -end portions of said bridge inwardly of said legs providing bearings, a pair oi' side cutters on said bearings, a pair of outwardly facing ilanges on said bridge adJacent the inner end portions of said bearings providing koutwardlyi'aeing ball races for taking inward thrust from said side cut- 10 ters, the inner surface of each of said legs being provided with inwardly facing ball races adapted to take outward thrust from said side cutters, the bearing portions of said bridgehaving radial ball races complementary to said end thrust receiving races respectively, and each of said cutters having a pair oi ball races facing radially inwardly and toward the opposite ends of said cutters respectively, and balls in said ball races for taking the thrusts and radial loads from said cutters.

MICHAEL D. CARLE'ION. 

